Ball plunger with brim

ABSTRACT

An object of the present invention is to provide a ball plunger wherein a main ball of the ball plunger is rotated surely and smoothly, when a mold, jig or other article is fixed, positioned, or transported. Another object is to control and keep constant the main ball projection height from a surface fixed to the ball plunger. A plurality of the sub balls are accommodated on the bottom portion of the ball roller which farther accommodates the main ball on the sub balls, thereby reducing the rolling friction between the main ball and the sub balls. Thus, the main ball rolls smoothly. The ball roller and the spring is inserted into the casing. Finally, the spring is fixed to the casing by the coupling ring such as a c-shaped ring.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a ball plunger with a brim on a surface of the ball plunger, wherein a main ball is rotated surely and smoothly, by employing a plurality of small balls smaller than the main ball which are in contact with the main ball, in order to reduce a rolling friction of the main ball.

[0003] 2. Description of the Prior Art

[0004] Some of conventional ball plungers are designed in such a manner that the main ball is stroked by a spring. Therefore, the main ball can not be rotated smoothly, although a load and stroke length of the main ball can be controlled.

[0005] Other conventional ball caster with a spring is designed in such a manner that an impact by a weight of an article during transportation is absorbed Therefore, the conventional ball caster can not be utilized for a plunger which can control the load and stroke.

[0006] Further, another conventional ball plunger is designed in such a manner that the plunger body is tapped by a male screw. Therefore, the ball projection height from a surface of a target object of the ball plunger is merely controlled by a screw rotation of the ball plunger.

SUMMARY OF THE INVENTION

[0007] An object of the present invention is to provide a ball plunger wherein the main ball of the ball plunger is rotated easily and smoothly, and the ball plunger controls the load and stroke of the main ball and the ball projection height form a surface of an object fixed to the ball plunger. Concretely, an object of the present invention is to provide a ball plunger wherein a main ball of the ball plunger is rotated surely and smoothly, when a mold, jig or other article is fixed, positioned, or transported.

[0008] The ball plunger of the present invention comprises: a ball roller; a spring; a casing for accommodating the ball roller and the spring, wherein the ball roller is stroked in the casing.

[0009] The casing has a brim for stopping the ball plunger on the surface of the object.

[0010] According to the present invention, the main ball is shifted upward and downward by using the spring. Further, the main ball is rotated surely and smoothly, due to the reduction of the rolling friction. Accordingly, the main ball is rotated surely and smoothly under the load applied in a transverse direction perpendicular to the stroke direction of the main ball. Due to the smooth rotation of the main ball, machines, products or articles are set and moved without being damaged.

[0011] Further, according to the present invention, the ball plunger is fixed quickly and surely to an object surface, with fixed ball projection height kept constant, due to the brim which prevents the ball plunger from proceeding any more when the brim contacts the object surface.

BRIEF EXPLANATION OF THE DRAWINGS

[0012]FIG. 1 is an exploded perspective view of the ball plunger of the present invention.

[0013]FIG. 2 is a fragmentary cross sectional view of the ball plungers of the present invention fixed to an object plate. The left plunger is a plunger without any tapped screw on the outer surface of the ball plunger of the present invention, while the right plunger is a plunger with a male screw on the outer surface of the ball plunger of the present invention.

PREFERRED EMBODIMENT OF THE INVENTION

[0014] Preferred embodiment of the present invention is explained, referring to the drawings.

[0015] The ball plunger of the present invention comprises: the ball roller 1; the spring 2; the casing 3; the brim 4; the coupling ring 5; the main ball 6; the sub balls 7.

[0016] A plurality of the sub balls 7 are accommodated on the bottom portion of the ball roller 1 which further accommodates the main ball 6 on the sub balls 7, thereby reducing the rolling friction between the main ball 6 and the sub balls 7. Thus, the main ball 6 rolls smoothly.

[0017] The ball roller 1 and the spring 2 is inserted into the casing 3. Here, the spring 2 may be connected together beforehand with the ball roller. Alternatively, the spring 2 may be inserted independently into the casing 3.

[0018] Finally, the spring 2 is fixed to the casing 3 by the coupling ring 5 such as a c-shaped ring. Thus, the spring 2 is fixed to the casing 3 precisely at a prescribed length of the spring.

[0019] Further, the casing 3 has the brim 4 on its outer edge where the main ball is projected. The brim 4 prevents the ball plunger from proceeding any more in the object, when the brim 4 contacts the object surface.

[0020] Thus, the ball projection height 8 is kept constant. 

What is claimed is:
 1. A ball plunger fixed at an object surface, which comprises: a plurality of sub balls; a ball roller for accommodating said plurality of sub balls; a main ball disposed on said plurality of sub balls; a spring for supporting said ball roller; a casing which accommodates said ball roller and said spring; a brim on an outer circumference of said casing for stopping said ball plunger at a surface of said object; and a coupling ring for fixing said spring to said casing, wherein: said sub balls reduce an rolling friction of said main ball and said coupling ring fixes said spring at a prescribed length of said spring.
 2. The ball spring according to claim 1, wherein an outer surface of said casing is tapped by a male screw.
 3. The ball plunger according to claim 1, wherein said coupling ring is a c-shaped ring. 